3.1 Patient and antiviral use
A total of 115 867 prescription records of baloxavir and NAIs were
identified in 115 238 children. Their median age was 10 years, with
interquartile ranges from 8–13 years. Males accounted for 53.3% of
cases (61 396 out of 115 238). Of these children, 26 % had at least one
comorbidity relevant to complicated influenza infection (Table 1).
Of all prescription records (n = 115 867), baloxavir accounted for 43.2
% and, as for NAIs, oseltamivir, laninamivir, and zanamivir accounted
for 16.2%, 28.1% and 12.5%, respectively. Specific virus types were
recorded in 75.1% of cases (type A: 74.2% [86 023 cases] and type
B: 0.83% [964 cases]). The peak of prescription was observed in
January 2019, coincident with overall influenza activity during the
2018/2019 season in Japan (Figure 1) [13].